Telephone test set with line resistor



Aug. 29, WRONKE TELEPHONE TEST SET WITH LINE RESISTOR Filed Nov. 9, 1948' f'zz/enl or' anZ /wrgy L. wreaks Patented Aug. 29, 1950 UNITED STATES PATENT OFFICE-H,

TELEPHONE TEST SET WITH LINE RESISTOR Anthony L. Wronke, Chicago, 11].

Application November 9, 1948, Serial No. 59,145

This invention relates to hand telephone test instrument or test set more particularly for use by telephone line men who are installing or'repairing a telephone circuit and are required frequently to work on telephone wires strung on 2 Claims. (01. 179-175) poles in alleys, streets and other outside places relatively far removed from both the particular installation involved and the central ofiice.

Particularly in connection with so-called nickel first lines which include a dial for calling a number, no dial tone is heard indicating that the line is in order for a call until a five cent coin is deposited by the user whereupon a dial tone is heard and the user knows that-the line is then in order for making a call by the use of the diaL. For this reason, when a telephone repairman cuts into such a line, by connecting one lead of his test set with the ring or battery side of the line and the other lead of his test set with the tip of ground side of the line, he does not get a. dial tone and therefore does not know whether the line is or is not in order, or whether it is the line which he intends to work on, and to ascertain this he must first call, from another line that is in' working order, the central oflice tester by using the dial of his test instrument. This is time consuming and requires frequenttrial and error. 7

The present invention aimsto provide means on histest instrument for insuring that a dial tone would be heard if the line he cuts into'is in order, by including in the test instrument a resistance in parallel with the ground lead of the instrument and a third clip for example for selectively grounding the resistance.

The invention will be readily understood and the accomplishment of the foregoing and other objects and advantages will be apparent from the following description, taken together with the accompanying drawings of an illustrative embodiment of the invention, and in which drawmgs:

Figure 1 is a view of a telephone test instrument embodying the present invention; and

Figure 2 is a simple circuit diagram illustrative of the structure of Fig. 1 and of a useful application thereof for the present purposes.

Referring in detail to the illustration of the drawings, the numeral ll may indicate a conventional hand telephone test set of the so-called French type having a receiver element l2 and a transmitter element I3, and commonly incorporating an impulse transmitting device such as the usual rotatable finger calling dial l 4. A cable l5 extending from the hand set Il may incorporate the usual test leads l6 and I! terminating in spring clips I 8 and I9 respectively by which the test instrument Il may be cut into a telephone circuit, the lead l6 being What is known as the ring or battery side lead and the lead 11 being known as'the tip or ground lead. As indicated in Fig. 2, the lead [6 goes to the receiver element and the lead I! to the transmitter element. A contact including connection within the instrument completes the series connection between the receiver and the transmitter. The Wiring for the dial 14 may be conventional and as somewhat diagrammatically indicated at I00 in the connection 20.

In accordance with the present invention, I connect an auxiliary lead 2| through a resistance 22 with the tip or ground lead I! and ,pro-

'Vide an auxiliary spring clip 23 for the auxiliary lead 2!, thus providing the test instrument H with three leads instead of the conventional two leads.

When the test instrument of my present invention is used by the telephone line man, for example, he will first engage the spring clip I8 with the ring or battery Wire of the circuit which he is attempting to test and the spring clip IS with thetip or ground wire of the circuit. Then he may engage the auxi1iary clip 23 with a grounded object or other so-called ground accessible at the location in which he is working such as a ground strip, ground cable, guy Wire, water pip or the like.

The resistance 22 is substantial and is say between 900 and 1100 ohms. I have found resistance of the order of 1,000 ohms to be desirable and suitable for the purpose.

Fig. 2 indicates a simple illustrative circuit in that a central office is suggested by the rectangle 24 in which may be located the connection terminals 25 and 2B, the dial tone generator 21 and a relay 23, The line which the line man may be testing is indicated by the wires l6a and Ila, representing the ring and tip sides of the line respectively and connected with the terminals 25 and 26 respectively through which a trunk connection may be made at the central office in the usual manner which need not here be described. It is suflicient for present purposes to indicate the wire 29 which connects the terminal 25 (through the dial tone generator 21) with the armature 3| of the relay 28, and the wire 30 which connects the terminal 26 with the contact 32 of the relay. The armature is as shown adapted to contact the contact 32 and close a circuit through the dial tone generator 21 to actuate the latter and set up a dial tone in the line l6al1a, which, if present, will be heard in the receiver element l2 when the test instrument is hooked in as already described.

The winding of the relay 28 is connected as at 33 on one side with the terminal 26 and on the other side as at 34 with one side, in this instance the positive side, of a battery 35, the other side of the battery being grounded as at 36. With a test instrument not equipped with my auxiliary device 2l2223 the dial tone will not be heard in the test instrument H even though the line is in order, because of the fact that the relay 28 will not be energized to close the contact 32 with the armature merely by connecting the lead It with the wire ISa'and the lead I! with the wire Ha, but, when the device 2l--22--23 of my invention is employed, and the lead 2| is connected with a ground suchasat 31, through the resistance 22, the relay 20 will be energized to close contact 32. and a circuit made which will actuate the dial tone generator 21. A dial tone will then be heard in the test instrument, and the line man will not need to call the central ofiice tester but may call the operatoratthe central ofiice direct bythe use of the dial M to ascertain whether the line |al1a is the lineupon whichhe is working, thus saving time.

It will be understood that the foregoing discussion may relate primarily to a telephon line going to .a coin box and in which the dial tone is notheard until after the user has dropped a five cent coin into the box. My attachment 2|-2223 thus functions in efiect for the line man as the equivalent of the dropping of the f coin into the box, which box would not be ordinar-ily accessible'to the lineman working out of-doors, say on the line, and particularly when he is working on a pole or on a terminal box located on the rear outside Wall of a building. 7

In some telephone systems although the installer or repair man can get dial tone by going in on the line, he cannot get the operator, to

identify the line for him, because the central 4 line man to call a subscriber from the pole or terminal box without the use of a nickel or without the subscriber being charged for such call.

The term clip is intended to include any suitable contact making instrumentality.

It will be understood that my invention is not limited to details of construction shown for purposes of exemplification. For example, resistance 22* could :be built into'the, test'set for convenience or compactness, andother changes might. be made without departing from the invention and while still falling within the scope of the appended claims.

Having described my invention, what I here claim is: V

1. Ina telephone hand test instrument embodying a receiver, a transmitter, said receiver and'transmitter each having a first side and a second side, connections within each of said receiver and transmitter between the first and second sides thereof, a. connection. from a first side of the receiver to a first side of the trans,- mitter, an impulse transmitting device having contact means .inrseries with said connections, the combination of, a lead to said second side of the receiver, another lead to saidsecondside of the transmitter, said leads also being in series with said contact means, one of saidleads serving as a ring side lead and the other as a tip side lead, clips on said leads respectively, a third clip for. connecting to ground, a lead from said third clip connected to the tip side lead,.and a resistance in said third cliplead;

' 2. The structure. of claim 1 wherein the resistance is of the order of 1,000 ohms.

ANTHONY WRQNKE.

REFERENCES CITED.

The'following: references are of record" in the file of this patent:

UNITED STAT-ES LPATEN'I'S Long June, 2,. 1936 

